This invention arose out of a desire to provide high liquid pressure operation without the need to incorporate accumulator circuitry in the liquid circuit. It is known, for example, that the volume of liquid, namely, water at 10,000 psi, will be reduced in volume by approximately 2.7% from the same quantity of water at atmospheric pressure. Similarly, it is known that the same quantity of liquid (water) at atmospheric pressure will be compressed by approximately 7.5% at 36,000 psi. Thus, in operations where the pressure on a liquid is elevated to substantially high pressures, such as in the range of 30,000 psi to 40,000 psi, and assuming that a liquid utilizing load is connected in circuit with the high pressure liquid supply, the pressure on the liquid will be substantially reduced at a time when the pressure on the liquid is building, but yet liquid is exiting the system to the liquid utilizing load. One of ordinary skill in the art has, in the past, utilized accumulator circuitry for supplying an adequate amount of liquid at a high pressure in order to maintain the pressure at the outlet of the liquid distribution system at a fairly constant level. Accumulators subjected to a pressure of between 30,000 psi and 40,000 psi are expensive components in any liquid system and their elimination from any circuit would be financially beneficial.
Accordingly, it is an object of the invention to provide a device for elevating a pressure acting on a liquid to a substantially high level and without incorporating an accumulator within the liquid circuit.
It is a further object of the invention to provide a device for elevating a pressure acting on a liquid, as aforesaid, wherein at an inlet to the system, a liquid is supplied at a first positive pressure and extracting from the system a liquid at a second positive pressure substantially greater than the first pressure resulting in a liquid compressibility factor at the inlet that is much less than the liquid compressibility factor at the outlet of the liquid system so that a control device accommodates the differential in compressibility of the liquid without resorting to the use of a liquid accumulator circuit in order to maintain, at an established throughput, the second pressure substantially constant.
It is a further object of the invention to provide a device for elevating a pressure acting on a liquid, as aforesaid, wherein at least a pair of elongated, hollow, cylindrical housings are provided each having a plunger reciprocally movable therein, the plungers being freely movable between the ends of the cylinder housings in response to the introduction of pressurized liquid into a selected end of each thereof to facilitate a driving of the plungers toward the other end.
It is a further object of the invention to provide a device for elevating a pressure acting on a liquid, as aforesaid, wherein a control device is provided for effecting a pressure imbalance on one side of the plunger in a second cylinder housing before the plunger in the first cylinder housing arrives at an end of a stroke path therefor and whereat the flow rate from the second cylinder housing begins to diminish so that a flow rate caused by a beginning stroke path of the plunger in the second cylinder housing will supply a flow rate balancing amount of liquid to a common outlet from the liquid system at substantially the same second pressure so as to maintain substantially constant the second pressure at the common outlet from both the first and second cylinder housings.
It is a further object of the invention to provide a device for elevating a pressure acting on a liquid, as aforesaid, wherein the ratio between the pressures at the inlet to the liquid distribution system and the liquid exiting the outlet from the liquid distribution system is 1 to 4.
It is a further object of the invention to provide a device for elevating a pressure acting on a liquid, as aforesaid, wherein a plurality of valves are sequentially activated with a portion of the operative cycle of one valve overlapping the cycle of operation of the valve immediately preceding the one that is being activated.